A vulnerability in the Linux kernel vmxnet3 driver allows unauthenticated attackers to trigger a denial of service via a crafted network packet.

The vmxnet3 network driver fails to correctly parse Geneve-encapsulated packets, leading to an incorrect assumption about header lengths and triggering a BUG_ON condition. This vulnerability can be triggered by an unauthenticated remote attacker sending specifically crafted network traffic to the affected system.

The exploitation of this vulnerability results in a kernel panic, which causes an immediate system crash and denial of service. Given the CVSS score of 7.5, this high-severity flaw poses a significant risk to the availability of critical infrastructure, such as virtualized network appliances and servers utilizing the vmxnet3 interface. Unscheduled downtime resulting from this crash can disrupt business operations and impact service level agreements.

Immediate Action: Update the Linux kernel to version 5.10.265, 5.15.216, 6.1.183, 6.6.148, or a later stable release provided by your distribution vendor.

Proactive Monitoring: Monitor system logs for repeated network driver errors or unexpected kernel panics that may indicate an attempt to trigger this crash.

Compensating Controls: If patching is not immediately feasible, restrict network access to the affected interfaces using firewall rules to block suspicious or malformed Geneve-encapsulated packets.

Public Exploit Available: No — there is no confirmed public exploit available.

This high-severity vulnerability requires immediate attention due to the ease with which a remote attacker can cause a system-wide denial of service. Organizations running virtualization environments that rely on the vmxnet3 driver should prioritize kernel updates to the specified versions or newer to eliminate this risk. Apply these updates as part of your standard emergency patch cycle to ensure continued system stability and uptime.